feat(layers): Recent Imagery — open satellite imagery for a selected box (#716)

Select a box on the world and browse the last 30 days of open satellite imagery over it, keyless: NASA GIBS Harmonized Landsat Sentinel-2 (30 m) and the VIIRS daily overview (250 m), with a day strip, IMAGE / VS BASEMAP / A / B modes with a swipe divider, PNG export and share links. The before/after swipe from the Nepal scene moves into shared modules so both use it.

Co-authored-by: manjunath22466 <[email protected]>

src/app/constructCatalog.test.mjs

@@ -39,7 +39,7 @@ test('catalogs construct distinct layers and classification from their supplied
     signal: b.signal,
     surface: fixtureSurface(b.signal),
   });
-  assert.equal(first.layers.length, 26);
+  assert.equal(first.layers.length, 27);
   assert.notEqual(first.weatherClock, second.weatherClock);
   await first.weatherClock.setTarget('2026-09-21T12:00:00.000Z');
   assert.match(